Disclosed herein are chromium carbonyl complexes of polyamides containing units derived from aromatic diamines, in which 10 to 90% of those units are complexed with a chromium carbonyl compound, and a process for making the partially complexed polyamides.
Polyamides containing units derived from aromatic diamines are known. Aramids are a type of polyamide in which the polymer consists essentially of monomeric units derived from aromatic diamines and aromatic diacids. Some aramids, such as those derived from p-phenylenediamine and terephthalic acid [herein sometimes PPD/T or poly(p-phenyleneterephthalamide)], are not generally soluble in organic solvents, making it difficult to fabricate useful items from them. It has been found that partially complexing the aromatic diamine used in these polymers with a chromium carbonyl compound (and hence the aromatic diamine units in the polymer are also partially complexed) renders the polymers relatively more soluble in organic solvents.
J. Jin and R. Kim, Polym. J., vol. 19, p. 977-980 (1987) report the preparation of polyamides in which the aromatic diamine derived units are completely complexed with Cr(CO).sub.3. No mention is made of partially complexed polymers, and the resulting solutions are not reported to be lyotropic.